1. Field of the Invention
The present invention relates to a spatio-temporal noise removal method using block classification and a display device using the same for removing spatio-temporal noise by performing spatio-temporal filtering depending on whether a block in an image is a uniform region formed with similar pixel values.
2. Description of the Related Art
In the conventional image noise removal method, if a current field is inputted with noise, the conventional noise removal method removes the noise from the current field based on motion compensation or motion estimation calculated by using a previous field from which noise inputted prior to the current field has been removed.
In detail, the conventional image noise removal method calculates a motion vector between a current field and a noise-removed previous field, compensates for motion, and uses motion estimation between the current field and the noise-removed previous field. The motion-compensated field and a current field for noise removal are used for the one-dimensional temporal filtering or the three-dimensional spatio-temporal filtering. In this case, the finite impulse response (FIR) filter can be used at the time of the one-dimensional temporal filtering, and the infinite impulse response (IIR) filter can be used at the time of the three-dimensional spatio-temporal filtering.
However, at the time the temporal filter is used for noise removal, there exists a problem that noise appearing in space is not effectively removed. Further, at the time the spatial filter is used for noise removal, there exists a flickering problem of varying a brightness difference between fields continuous in time since time-dependent relationships between fields are not used.
Therefore, even a spatial filter for noise removal is required to use time information, and a noise removal method is required to remove noise by using a temporal filter and a spatial filter using time information, depending on a region of an image.